Toaster



y 7, 1953 c. J. FOSTER 2,644,392

TOASTER I Filed June 6, 1949 5 Sheets-Sheet 1 Ai -i INVENTOR.

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TOASTER Filed June 6, 1949 5 Sheets-Sheet. 2

IN VEN TOR.

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' TOASTER Filed June 6, 1949 5 Sheets-Sheet 4 IN V N TOR.

July 7, 1953 Filed June 6, 1949 C. J. FOSTER TOASTER 5 Sheets-Sheet 5 INVENTOR.

Patented July 7, 1953 UNITED STATES PATENT OFFICE TOASTER CyrilJ. Foster, Chicago, 111., assign-or to Eta, Inc.,

Niles, Mich, a corporation of Michigan Application June 6, 1949, Serial No. 97,380"

3 Claims. 1

This invention relates to toasters for bread and the like, and more particularly to toasters of the automatic type which embody apparatus for effecting control of the time of the toasting cycle.

One of the objects of my invention is to provide an electrically operated automatic toaster for sliced bread and which has parts for effecting the commencement of the toasting cycle upon theinsertion'of a slice of bread, the timing of which'cycle is adjustable and automatic, and at the end ofwhich cycle the heating element is deenergized and the toasted bread madeavailable'for use;

As another object, the invention has within itspurview the provision of an automatic electrically operated toaster incorporating a toasting cycle timing mechanism which embodies temperature responsive elements separately operable for determining the toasting time and sequentially used in a manner such that the toaster may be used time after-time with one temperature responsive element in use while another is returning to its normal state.

My invention further comprehends the provision of a toaster for sliced bread having a toasting compartment defined by a housingwith curved heat reflecting walls adapted efiectively and efficiently to concentrate the heat over the surface of abread slice in a toasting position within the housing.

Another object of this invention is to provide an automatic-toaster for bread slices and wherein the toasted slices are released at the end of the toasting periodfor movement by gravitational force away from the heated portion of the toaster.

It is a further object of the invention to pro vide an electrically operated automatic toaster which, after thepreselection of a desired toasting time, requiresonly the manual insertion of bread slices to eifect its operation.

Other'objects and advantages of the invention will be apparent from the following description and the accompanying drawings in which'similar characters of reference indicate similar parts throughout the several views.

Referringto the five sheets of drawings:

Figs. 1 and 2 are respectively front elevational and top plan views of a toaster embodying a preferred form of my invention, and each of which views shows the toasting positionsof bread slicesand the delivery positions-of finished toast slices;--

Fig. 3 is a diagrammatic exploded view indicating the general arrangement and relationships of parts of my preferred toaster, aswell asthe circuit connections of the electrical parts thereof;

Fig. 4 is a side sectional view of my toaster wherein the section is taken substantially, on a line 4-4 of Fig. l and in the direction indicated by arrows;

Fig. 5' isa top plan view of a portion of the toaster structure wherein the top part of the housing is removed to show the internal parts; Figs. 6 and '7 are fragmentary side sectional views of a portion of the toaster structure, and inwhich views different operating positions .of certain of the parts aredepicted;

Fig. 8 is a fragmentary top plan view illustrating my preferred structure for certain ofthe operating parts of the toaster;

9 isa fragmentary elevational view showing parts of my. toaster, structure and their relationships, as viewed from within the enclosure for such parts, and

Fig. 10 is a fragmentary bottom view depicting 4 the construction and relationship of certain op- My toaster, in the form illustrated, is not only,

adapted to automatic operation so that the toasting time cycle is automatic and the toast made readily available for use at'the end of the time cycle, but it is also my preference to'provide av toaster. structure constructed and arranged in a manner such that the .bread slices, or the, like, pass through the toasting zone of the housing for release to an accessible position; rather than being retained completely or partially within the toasting zone a the end of "the.

toasting cycle. I

As depicted in Figs. 1, 2 and 4, my preferred housing ll comprises a substantially spherical metal shell having upper and lowerportions l8 and [9 respectively which are each substantially hemispherical and which, in their assembled relationship, have overlapping marginal portions 20 and 22,v with the inner marginal portion 22 offset inwardly to effect the presentation of a relatively smooth external surface. Slot type openings 23 and 24 are provided in the housing portion 18 through which bread slices are inserted into the toaster for toasting. Directly below the openings 23 and 24, and in the lower portion 19 of the housing, additional slot type openings and 26 are provided, through which latter openings the toasted bread slices pass from the toasting zone within the housing ll. Thus, the openings 23 and 25 provide one aligned pair of openings for the passage of a bread slice into and from the toaster housing, while the openings 24 and 26 provide another such aligned pair.

The top openings 23 and 24 as well as the bottom openings 25 and 26 are spaced apart and have opposed edges lying in substantially parallel planes, which planes, in the present instance, are symmetrically disposed on opposite sides of a central plane through the housing.

Inv the preferred type of base, the front and rear walls 2! and 28 respectively extend upwardly, tapering to a relatively narrow top section at their mid-portion, so as to fit between the bottom openings 25 and 26. Also, opposed top wall portions 29 and 30 are similarly and oppositely curved outwardly as they extend downwardly from the relatively narrow top mid-portion of the base, thereby to form chutes extending downwardly and outwardly below the lower openings 25 and 26. The toaster housing ll being secured to the top of the relatively narrow base mid-porton, slices of bread or the like, as 32 and 33, inserted into the toaster housing through openings 23 and 24 respectively, as depicted in Figs. 1 and 2, will be discharged, after toasting, through the lower openings 25 and 26, and will gravitate to positions such as those indicated by the toast slices 34 and 35 respectively. As a further consideration, the interior of the base i5 is hollow to provide an enclosure for some of the operating parts of the toaster at a position somewhat isolated from the heated toaster housing a central and inverted substantially U-shaped frame 31, which frame serves to hold the housing portions l8 and I9 together, in addition to providing a main supporting frame. Fastening means, such as screws 36 and 39, extend through internal flanges 40 and 42 respectively which are integrally formed on the relatively narrow top mid-portion of the base l5 and through the lower portion l9 of the housing, as well as through formed end portions 43 and 44 on opposite sides of the frame 31. These screws thus secure the toaster housing I! to the base l5 and secure the frame 31 within the lower portion l9 of the housing. Fastening means, such as screws 45 (Fig. 1), are utilized to secure the upper housing portion l8 to a curved mid-portion 46 of the main frame.

Substantially rectangular metal end plates 41 and 48 are secured in practically parallel and opposed relationship to straight side portions 49 and 5B of the frame 31. Flanges 52 and 53 at opposite sides of the end plate 41 and flanges 54 and 55 extending along opposite side edges of the end plate 48 have sheets of insulating material 56 and 51, such as mica sheets, secured thereto, so that they span the space between opposite sides of the end plates in practically parallel relationship. These insulating sheets carry strands of resistance wire in spaced relationship to provide heating elements 58 and 59 facing inwardly toward one another. The heating elements 58 and 59 have an area sufficient to toast the face of an ordinary slice of bread, and are disposed in planes lying outside of the toast receiving and outlet openings. In a plane lying between the spaced openings, at third insulating sheet 50, of mica or the like, is carried by inwardly projecting tabs 62 and 63 on the end plates 41 and 48 respectively. This insulating sheet carries a heating element 64 which is exposed on both faces of the insulating sheet and is adapted to heat the adjacent surfaces of two bread slices at the same time. For supporting the bread slices between and in spaced relationship laterally between the heating elements, I provide spaced pairs 65, 66, 6'! and 68 of diagonally disposed wires 69 and 10; two pairs of such wires being mounted in spaced relationship between each of the outside heating elements and the intermediate heating element, with the spacing between adjacent pairs sufficient to receive a bread slice. These wires, in the disclosed toaster structure, each have end portions 12 and '13 extending through openings in the end plates 41 and 48, and bent to hold them in place.

For supporting the bread slices in the toasting zones between the heating elements during a toasting cycle, trap elements 14 and 15 are provided. These trap elements are hingedly supported for swinging movement between supporting and retracted positions by rods 16 and 11 respectively which each project through aligned bearing openings in the end plates 41 and 48. In the disclosed structure, the supporting rods 16 and 11 are in substantially parallel relationship at the mid-portion of the plates and below the respective heating elements, so that the trap elements swing outwardly in opposed directions to their retaining positions, as depicted in Figs. 4, 5 and 7, and as illustrated in solid lines in Fig. 3. In their retracted positions, the trap elements drop to positions in which they hang downwardly from the rods 16 and 11, as shown in Fig. 6, and as indicated in dot and dash lines at Ma and 15a, in Fig. 3. Actuation of the trap elements 74 and 15, to effect their retention in the retaining position, and to release them for movement to the retracted position, is effected by an arm '18 secured to an end of a rotatable operating shaft 19; the arm 18 being swingable about the axis of the shaft 19 in a plane immediately below the rods '16 and 11 which support the trap elements, so that when disposed in a position lateral to the rods, the trap elements are supported in their retaining positions, as shown in Figs. 4, 5 and '7. When the arm 18 is longitudinally disposed in substantially parallel relationship between the rods 16 and TI, as shown in dot and dash lines at 18a in Fig. 3, and as illustrated in Fig. 6, the trap elements gravitate to a dependent position relative to the rods. thereby to release retained toast slices for passage through the outlet openings 25 and 26 at the bottom of the toaster housing.

In the disclosed embodiment of my invention, the shaft 19 extends upwardly from a. bearing collar secured to the mid-portion of the base plate 36 (Fig. 4) and through a bearing bore 82 in the lower housing portion I 9. A collar 83 secured to the lower end of the shaft rests against the surface of the bearing collar 80 to support tid ngs-gigs the shaft; Also, irfthe disclosed structure;theshaft andthe arm'lB are adapted to actuation in sequential 90 degree increments of movement.- My preferred actuating mechanism for effecting the sequential 90'degreeincrementsof movements of the shaft 19, includesa'ratchet wheel Bldi'iVingly secured tothe shaft 19 within'the hollow portionof the basel5 and having periph j eral notches 85 spacedin 90 degree relationship Also; drive" pins 86 are i secured to and project axially from the face of relative to one another.

the ratchet wheel in 90 degree spacedrelationship relative to one another at circumferentially" preselected positions relative to th'epositionsoff" the notches 85. As shown in'Fi'gsi 3, 4 and'8;

asolenoid 81 havinga movablearm'ature 88--drivingly connected to a pawl Bil-disposedto engage the pins 86, isutilized to produce thefsequential increments of shaft movement. linear movement of the solenoid armature 88 "is engages'an adjacent oneof the drive pins, as

shown in Fig. 8. The pawl 89 is connected to the end of the armature 88 for limited swinging movement laterally of the'armatureaxis by a pin 93. Also, atorsion spring'fllhavingend portions 95 and 9G engagingopposite sides ofthe pawl and armature respectively on opposite sides'of the pin 93 axially of the armature, biases" the pawl toward the drivepins relative to the armature. A tension spring 9! having one end connected to the" pin 93- and its other end anchored to astationary pin 98 biases 'the'ar'm'a' ture and its pawl tothe'normally'extended posi-' tions illustrated in Fig. 8.

As depicted in Fig. 4, the solenoid 81' is preferably-provided with a magnetic core 90 for the improvement of its magnetic efiiciency.

zation of the solenoid draws" the armature into the winding from the extended position depicted in Fig. 8. During suchmovement, the hook portion 90 of the pawl is engaged with one of the drive pins 85 and effects rotational move} ment of the ratchet wheel 84 and shaft through 90 degrees, and until thesucceeding one" of the drive pins engages a projecting' stop sur-" face !03 on the end of the pawl89, as illus-' In this manner, the ratchet trated in Fig; 3. wheel and shaft are stopped at the endof the 90" degree increment of movement. Atthis position, the free end of aleaf type retaining spring [04 engages one of the'notches 85 in theperipher'y'of theratchet wheel to hold the ratchet wheel in the position into which itis actuated; the" other end of the retaining spring I04 .beingsecured to a support bracket I05 which extends upwardly from the auxiliary base plate I02, as shown in Fig. 4. From theactuated position illustrated in Fig; 3, the armature and pawl are" The axis of '20 disposed transversely and to one side'of the'axisof the'shaft l8, so'that ahook portion 9 0 onthe' pawl 89 normally engages oneof thedrive pins" 86, while a straight side surface'92 of 'the pawl- This core is supported'relative tothe ratchetwheel' by a bracket I00 which is secured to an auxiliary' base plate I02 above theba'se plate 36; EnergiL- tra'ete'd 'posiuons upon'the sequential "degree movements of the shaft which are produced by successive operations of the solenoid driven pawl.

Having thus provided for the electrical actuar tion-of thetrap elements, to control the retention and release-of toast slices, it is my further preferenceto provide controlsfor making the operation of the toaster'as fully automatic as- For this purpose, I not only providepractical. a switch mechanism I06 actuatedby the inser' tion of one or two bread slices in the'toasting: zone to initiate operationof the toaster,-but I also provide a'timing mechanism I01 for effecting automatic timing of the toasting cycle; both of which latter mentioned mechanisms are: adapted, through electric circuits, to effect operation of the solenoid to control the positions Although there are'variof the trap elements. ous types of adjustable timing mechanismswhich are-suited to use for controlling-the timing cycles of electrical toasters, such as that shown herein; it is my preference to utilize such a mechanism" which is' dependent upon the flexureof a bi-' metallic strip and to provide a structure and arrangement such that toasting cycles may'follow in close sequence without the necessity-of consciously waiting for a return of the bimetallic strip to normal after flexure. V

Asillu-str-ated inFigs l and 10, the disclosed timing mechanism includesan elongated" bime tallic'strip I08 secured to the lower end'ofthe shaft 19 between the collar 83 and a disk I09,

with its end portions H0 and ll2projectin'g equally. in opposite directions and normally in substantially perpendicular relationship fromthe axis of the shaft [9. As illustrated in Figs. 3,--

4 and 9, a single pole, double throw switch 1 His mounted for limited swinging movement on the.

interior of the front wall 21 of the base IS with an actuating element I I4 at a position for engage ment with the end portions H0 and H2 of the bimetallic strip when those end portions arebrought into alignment with that actuating ele ment by rotation of the shaft l9 to preselected positions. Actually, the relative positions of the" bimetallc strip and the switch I I3 are determined in relationship to thesequential increments of movement of the shaft 19'which are determined by. the solenoid and its accompanying ratchet mechanism, as well as in relation to the operat-" ingpositions of thearm 18 and the trap elements actuated thereby. As shown in Fig. 3, in each instance, when the trap elements 14 and I5 are in their bread slice retaining positions, one' 'of the end portions of the bimetallic strip is in a position of alignment with the switch actuating element H4 for effecting actuation of the switch strip, as shown in dot and dash lines at 1 I00; and M in Fig. 3, which latter intermediate posi tions correspond to the positions'of the arm 18 in which the trap elements are open or retracted."

In the disclosed structure, the intermediate posi? tions of the end portions of the-bimetallicstrip. provide the normal positions of the partswhichare assumed when the heating elements are not energized and the toaster is not in use; it being understood that when the toaster is in use, with a' -toasting cycle in progress,-one of the end portions of thebimetallic strip is in its aligned position relative to the actuating. element I 14 of the switch H3.

This arrangement provides intermediate positionsof the end portions of the bimetallic The switch mechanism I66 which initiates the operation of the toaster upon the insertion of a bread slice into either of the toasting zones through one of the openings 23 or 24, includes a normally closed single pole, single throw switch I I5. Having a relative stationary contact I I6 and a movable contact III, the latter of which contacts carries an actuating element I I8 aligned for actuation by a cam portion I I9 of a movable switch operating element I20. The latter mentioned switch operating element I20, in the disclosed structure, as well as the cam portion II9 thereof, comprises a wire or light rod formed to provide aligned end bearing portions I22 and I23 supported for rotational movement in bearings provided by the flanges 54 and 55 on the end plate 48. Intermediate the end portions, substantially U-shaped portions I24 and I25 extend through slots such as I26 in the end plate 48 in substantially coplanar relationship and are biased to positions such that they normally project into the path of a bread slice inserted into one of the openings 23 and 24. The biasing force which normally holds the switch operating element I20 in a position such that the U-shaped portions I24 and I25 thereof project into the toasting zones, and which holds the cam portion II9 of that element in a position such that it holds th normally closed contacts of the switch H in an open position, is provided by a torsion spring I27 encompassing the end portion I22 of the switch operating element and having one end engaging the flange 54 and its other end secured to the portion I24 of the switch operating element. The normal positions of the U-shaped portions I24 and I25 of the switch operating element are indicated in dot and dash lines at I24a and I25a in Figs. 4 and 5, while the positions to which those portions are moved by the insertion of a bread slice are shown in solid lines in Figs. 4 and 5 and in dot and dash lines at I24!) and I25b in Fig. 3.

The switch II3 which is adapted to actuation by the end portions I I0 and H2 of the bimetallic strip includes a movable switch element I28 alternately engageable with stationary contacts I29 and I30. When the toaster is in its normal, nonoperating condition in which the bimetallic strip I09 has its end portions at positions indicated at IIOa and IIZa in Fig. 3, the movable switch element is at the position depicted in dot and dash lines at I28a, in Fig. 3, and is in engagement with the stationary contact I29. When the end portions H0 and H2 of the bimetallic strip are cool, and in their normal positions, they effect actuation of the movable switch element I28 to the position shown in solid lines'in Fig. 3, in which a circuit is closed to the stationary contact I30; it being understood that flexure of the end portion of the bimetallic strip, as the result of heat applied thereto, causes the movable contact element I28 to disengage the contact I 30 and reengage the contact I28.

, With these details of the normal switch positions and operations in mind, the operating sequences and my disclosed circuit arrangement may be understood by reference to Fig. 3. Leads I32 and I33 represent wires, such as a conventional attachment cord, by which the toaster is connected to a suitable power supply line. Starting with the assumption that the toaster is at its normal and non-operating position, with the end portions of the bimetallic strip at their intermediate positions, designated by IIOa and HM, and with the trap elements open, as depicted at Ma and a, the heating elements 58, 59' and 64 deenergized, and the switch operating element I 20 in a position such that the portions I24 and I thereof extend into the toasting zone as depicted at I24b and I25b, the sequence of toast operations is as follows: The attachment of the leads I32 and I33 to a powersource prior to th insertion of bread slices produces no result, because the circuit to the solenoid 81 is broken by the separation of the contacts I I6 and II! of the switch H5 and the circuit to the heating elements is broken by the normal separation of the contacts I 28 and I of the switch I I3. When, however, a bread slice is placed in the toasting zone, so that it moves the switch operating element I20, the contacts I I6 and I II of the switch II5 are closed to complete a circuit to the solenoid 81 through the contacts I28and I29 of the switch H3 and the contacts of the switch I I5. The resultant operation of the solenoid produces an increment of movement of the shaft I9 to close the trap elements I4 and I5, thereby to retain the bread slice, and moves the bimetallic strip to a position such that one end portion thereof actuates the switch II3 to break the circuit to the solenoid through the contacts I 28 and. I29 and to close a circuit from the power supply line leads to the heating elements through the contacts I28 and I30 of the switch I I3.

The circuit to the heating elements 58, 59 and includes a resistance heating element I34 in series therewith, which latter heating element is in closely spaced relationship to the end portion of the bimetallic strip when it is in engagement with the actuating element I I4 of the switch I I3. The toasting cycle is thus started with either one or two bread slices retained between the heating elements by the closed trap elements I4 and I5. With the completion of the circuit to the toaster heating elements 58, 59 and 64 through the heating element I34, the latter heating element gradually heats the end portion of the bimetallic strip to time the toasting cycle in proportion to the current flow through the heating elements. The resultant fiexureof the operative end portion of the bimetallic strip effects the return of the movable switch element I 28 of the switch II3 to its normal position of engagement with the contact I29 after the disengagement thereof from the contact I30. Disengagement of the contacts I28 and I30, of course, opens the circuit to the heating elements, thereby efiecting their deenergization. Residual heat effects complete operation of the switch I I3 to an extent that a circuit is again closed to the solenoid 81 through the contacts I28 and I29 and the contacts I I0 and I I! of the switch I I5, which contacts are closed prior to the release of the toasted bread slices from the toasting zone.-

The resultant second operation of the solenoid armature produces a second increment of movement of the shaft I9 to return the bimetallic strip to its normal intermediate position and to release the trap elements I4 and 15 for the passage of the toasted bread slices from the toaster. The departure of the toasted bread slices from the toasting zone effects a release of the switch operating element I20, so that it again opens the contacts IIS and II! of the switch II5, whereupon the cycle may be repeated.

It may be observed from the structure and operation as thus far described, that the end portions II Band H2 of the bimetallic strip alternately come into operative relationship with the actuating element I It of the switch II3. This alternating and sequential operation of the two end portions of the bimetallic strip provides a normal cooling time for the unused end portion insured/and the. toasting: time cycle may. be varied .byv manualadiustment. .As there depictedit is my preference thattheauxiliary base) plate E62 "shall. have anopening J35 through which the actuating element. I Hi of the. switch I I3. isacces- :sible to the end. portionsofthe bimetallic strip. n the face .of that auxiliary baseplateiover which the .end portions of the bimetallic strip --move into operative engagement with the switch actuating element. HA, I preferto provide a'plate .135, thesurfaceof. which is:curved so as to utilize the resiliencelofsthe-bimetallic strip for "flexing the .'end of the bimetallic .strip away, from the switch actuatingeleinent l M immediatelyprior to' its engagement with .thatractuating element, whereby to bring the bimetallic strip into contact with the switch actuating element with a sharp snap. Also, on the side of the opening 35 opposite the curved plate I36, I prefer to provide a flange [37 which faces the opening so as to provide a definite stop for the bimetallic strip and also so as to necessitate a predetermined amount of flexure of the used end portion of the bimetallic strip prior to its release of the switch actuating element and its movement away from the operating position.

As illustrated in Fig. 9, the switch H3 is sup ported for limited swinging movement relative to the base I5 of the toaster by means, such as a screw I38. A leaf spring his having one end secured to the auxiliary base plate Hi2 has its other end engaging the side of the housing of the switch I [3, so as to bias the switch in a direction relative to the screw I38, such that it tends e to move the actuating element H4 away from the position of contact with the end portion of the bimetallic strip. A shaft Ml! (Figs. 4 and 9) is mounted for rotation in a bearing bore M2 in the front wall 21 of the base l5, and carries an eccentric cam I43 on the side of the switch H3 opposite the spring I39. This cam is manually adjustable to determine the position of the switch H3 relative to the end portion of the bimetallic strip, whereby to effect a selection of the bimetal flexure necessary for producing operation of the switch, thus to vary the time of the toasting cycle. A knob hit on the shaft I40 exte rior to the base [5 provides a convenient manually operable element for adjusting the toasting time.

While I have illustrated a preferred embodiment of my invention, many modifications may be made without departing from the spirit of the invention, and. I do not wish to be limited to the precise details of construction set forth, but desire to avail myself of all changes within the scope of the appended claims.

Having. thus described my invention, what I claim as new and desire to secure by Letters Patent of the United States, is:

1. In an automatic toaster operable when connected to an electrical power source for toasting bread slices and the like, the combination comprising a housing having openings therein for the insertion of a bread slice and for the passage of a toasted slice from the housing, heating elements within the housing for toasting both sides of a bread slice when inserted through one of said openings, a trap element mounted within thehousing for retaining a bread slice therein whileto-asting and movable to release the toasted bread slice for passage from the housing by gravity through the other of said openings, a'switch actuating element mounted within thehousing and having a normal position fromwhich it is moved by the insertion of a bread slice, and :an

electrically operated control and actuating mechanism foreffecting actuation of the trap element and for controlling the toasting time, said controlwand actuating mechanismincluding a'first switch having normally open contacts and responsive to movement of said switch actuating element from its normal position for effecting clo- ;sure of the contacts, a second switch of .the single polekdoublethrow type normally biasedto a position such that it has norm-ally open and normally closed contacts, a solenoid having a winding connected to the-power source through the. contacts "by the normally-open contacts of the second switch for effecting return of the contacts of the second switch to their normal positions, and said normally open contacts of the second switch being connected to provide a circuit from the power source to the heating elements.

2. In an automatic toaster for bread slices and the like, the combination comprising a trap element supported for movements between an extended slice supporting position and a retracted position, a shaft supported for rotation at one side of the trap element, said shaft having a trap element engaging part thereon and driven thereby, said trap element engaging part having spaced projections thereon so as alternately to engage and disengage the trap element upon movements thereof through successive increments of preselected angular extent to effect movements of the trap element alternately to said slice supporting and retracted positions, a shaft driving mechanism including a solenoid actuated ratchet for turning the shaft step by step through angular increments of said preselected angular extent, bimetallic means secured to the shaft in fixed angular relationship to the trap element engaging part and having parts corresponding in space and position to the spaced projections on the trap element engaging part, a switch mounted at one side of the shaft in alignment for operating engagement with the parts of the bimetallic means when the trap element is in the slice supporting position, and said switch being electrically connected to the solenoid to efiect operation thereof in response to action of the bimetallic means.

3. In automatic heating apparatus for articles, the combination comprising a switch closed in response to presence of an article in the appa ratus and open in the absence of an article from the apparatus, a retainer for the article in the apparatus shifting between retaining and releasing positions, a heat-responsive member, a heater therefor, means mounting the heat-responsive member so as to cause successive movements thereof to bring one end of the member adjacent the heater, to take said end way from the heater, and to bring the other end adjacent the heater, means interconnecting the retainer and the heat-responsive member for causing the retainer to be in retaining position with either of said ends of the heat-responsive member adjacent the heater and the retainer to be in releasing position with neither end of the heat-responsive member adjacent the heater, actuating means for providing the aforesaid movements of the heat-responsive member, a contact element for connecting either the actuating means or the heater with a source of electrical power through said switch, and means engaging the end of the heat-responsive member adjacent the heater to shift the contact element to disconnect the actuating means from and connect the heater with the source of electrical power through said switch upon arrival of said end of the heat-responsive member adjacent the heater and to disconnect the heater from and to reconnect the actuating means with the ,source of electrical power through said switch upon appropriate heat response of the heat-responsive member.

CYRIL J. FOSTER.

References Cited in the file of this patent UNITED STATES PATENTS Number 12 Name Date Lincoln Dec. 10, 1929 Noble Oct. 11, 1932 Harter Jan. 3, 1933 Browning May 16, 1933 Rutenber Jan. 9, 1934 Rubens May 22, 1934 Avery Jan. 15, 1935 Rippl Sept. 29, 1936 Ireland Oct. 11, 1938 Graham Nov. 14, 1939 Myers Sept. 17, 1940 Gomersall Nov. 11, 1941 Ireland July 7, 1942 Sardeson Oct. 19, 1943 Olving Dec. 21, 1943 Purpura June 25, 1946 Meyers Apr. 6, 1948 Cox Mar. 29, 1949 Snyder Mar. 27, 1951 Chandler June 19, 1951 

